Observable API integration · API and Developers

API TTS

API TTS should measure time to first playable audio separately from time to completion. Connection setup, queueing, synthesis, transfer, decoding, and playback can each dominate a different workload.

Measure TTFA and completion separatelyProtect server-side credentialsReport p50, p95, and errors

Review current samples, pricing, limits, and documentation before production use.

Guide brief

What this page helps you evaluate

Build a speech integration with explicit timing, reliability, audio-format, and cost boundaries.

Reviewed

Integration path

Measure the whole speech request, not one vague latency number

Request 1Submit

Send a validated request over the documented endpoint.

Request 2Observe

Track acknowledgement, first audio, completion, and failure.

Request 3Deliver

Decode the documented format and apply retry or fallback policy.

Production readiness

  • Keep API keys out of source code and browser bundles.
  • Choose compatible voice and model identifiers.
  • Measure warm and cold paths separately.
  • Log request IDs and sanitized timing data without user text.

Developer brief

Design API TTS around observable boundaries

API TTS should measure time to first playable audio separately from time to completion. Connection setup, queueing, synthesis, transfer, decoding, and playback can each dominate a different workload.

Use the documented REST or WebSocket contract, protect API keys, validate responses, and record percentiles and errors—not a single best-case request.

API note 1

Request contract

Validate model, voice, text, language, and output settings for API TTS. Use one approved API TTS asset as the reference, then compare every candidate output against the same listening notes. Include the most consequential failure case in the API TTS pilot rather than postponing it until after automation.

API note 2

Timing model

Timestamp connection, acknowledgement, first playable audio, and completion. Record the script revision, voice, model, reviewer, and decision so the API TTS result can be reproduced after a later change. Document any manual cleanup required by API TTS; repeated cleanup belongs in the cost and capacity model.

API note 3

Failure path

Use bounded retries, idempotent behavior where supported, and clear fallbacks. Define a rollback for API TTS before automating volume, including which approved output or delivery path remains available. Monitor corrections and rejected output for API TTS; a rising review burden can matter before a technical failure appears.

Verified facts

What the product currently documents

Current source

Fixed public voice samples are available for review before purchase.

Samples are fixed previews, not a free custom-generation endpoint.

Review source
Current source

Current plans, balances, rates, limits, and commercial terms are published on the pricing page.

Pricing can change; use the linked page as the current source.

Review source
Current source

The current public Pay As You Go plan lists 2 concurrent requests.

Plan limits can change; verify the linked pricing page before deployment.

Review source
Current source

The documented v3 API supports asynchronous text-to-speech generation and status tracking.

Reviewed 2026-07-24.

Review source
Current source

The documented WebSocket endpoint streams live raw PCM float32 mono audio at 24 kHz for supported models.

This is an audio-format contract, not a numeric latency claim.

Review source
Decision notes

Questions specific to api tts

What should a low-latency benchmark report?

Report time to first playable audio and full completion separately, with percentiles, errors, workload, region, and connection state.

Can the WebSocket chunks be treated as MP3?

No. Follow the current streaming documentation for the live raw PCM format and use the completed file URL when appropriate.

Where should an API key be stored?

Keep it in a server-side secret store or environment configuration, never in source code or client-side JavaScript.

API and Developers

Test API TTS with your own acceptance criteria.

Review current samples, pricing, limits, and documentation before production use.

Read API Docs